Hippoidea is a Taxonomic rank of Decapoda known as mole crabs or sand crabs.[ Sand Fleas (Mole Crabs or Sand Crabs) Prime surf fishing bait][http://www.baymoon.com/~ilga/crabs/ All About Mole Crabs]
Ecology
Hippoids are
adaptation to burrowing into
, a habit they share with
Raninidae crabs, and the parallel evolution of the two groups is striking.
In the family
Hippidae, the body is almost
ovoid, the first
have no
, and the
telson is long, none of which are seen in related groups.
Unlike most other
Decapoda, sand crabs cannot
walk; instead, they use their
arthropod leg to dig into the sand.
Members of the family
Hippidae beat their
to swim.
Apart from the , hippoids can be found on beaches throughout the world. Larvae of one species have also been found in Southern Ocean, despite the lack of suitable sandy beaches in the Antarctic.
Classification
Alongside
and allies (Paguroidea),
and allies (
Galatheoidea) and the hairy stone crab (
Lomis hirta, Lomisoidea), Hippoidea is one of the four groups that make up the infraorder
Anomura.
Of the four, Hippoidea is thought to be the most basal, with the other three groups being more closely related to each other than to Hippoidea.
The fossil record of sand crabs is sparse,
- Albuneidae Stimpson, 1858
-
Albunea Weber, 1795
-
Austrolepidopa Efford & Haig, 1968
-
Harryhausenia Boyko, 2004 †
-
Italialbunea Boyko, 2002 †
-
Lepidopa Stimpson, 1858
-
Leucolepidopa Efford, 1969
-
Paralbunea Serène, 1977
-
Paraleucolepidopa Calado, 1996
-
Praealbunea Fraaije, 2002 †
-
Squillalbunea Boyko, 2002
-
Stemonopa Efford & Haig, 1968
-
Zygopa Holthuis, 1961
- Blepharipodidae Boyko, 2002
- Hippidae Latreille, 1825
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